The present invention relates to a radiation detection device having abutting or butting detection elements, as well as to a process for the production of said device.
The invention more particularly applies to the production of very long linear optical detection arrays, particularly for thermal imaging.
In the field of optical signal detection, it has progressively become necessary to produce ever larger components. For example, one of the major objectives of manufacturers is to manufacture very long linear photodetector arrays having more than 1000 pixels in line.
The high number of reading pixels required for such "array" type detectors excludes the manufacture of monolithic components for reasons of the fault rate and the limited sizes of the substrates on which said detectors are manufactured.
The most widely used procedure for producing very long photodetector arrays is the so-called butting or abutting method, which is e.g. described in the article "Recent developments on 12.5 .mu.m infrared detection buttable linear arrays", whose authors are J. P. Chamonal, C. Lucas, P. Bouchut, D. Blachier and P. Angelbaut, published in the Proceedings of SPIE Infrared Detectors and Focal Plane Arrays, vol. 1685 on 23.4.1992.
This method consists of juxtaposing on an interconnection substrate elementary photodetector arrays without any pixel loss, the total size of the equivalent array then no longer being limited by the aforementioned factors, namely the fault rate and the limited size of the substrates on which the photo-detectors are manufactured.
One of the possible abutting methods consists of producing detection elements or components incorporating photodetectors or pixels and cutting the ends of said components as close as possible to their end pixels in order to be able to mechanically juxtapose these components whilst maintaining the detection step size.
One of the methods permitting such a juxtapositioning is the so-called flip-chip hybridization method, according to which the components are hybridized by welding balls on an interconnection network support or on a reading circuit. In this case, the components receive the radiation to be detected by their rear faces.
The major difficulty of such methods is the cutting of the components without deteriorating the pixels close to the edge of the cuts or recesses (due to mechanical stresses inevitably caused by the cutting operation).
FIG. 1A is a diagrammatic view of two abutting detection elements 2, 4 hybridized on an interconnection network support 6 according to the flip-chip hybridization method.
FIG. 1B is the section I--I of FIG. 1A.